Multiple zone well production apparatus



March 5, 1968 p. v. cHENowl-:TH 3,371,717

MULTIPLE zoNE WELL PRODUCTION APPARATUS Filed sept. 21, 1965 6 sheets-snee*b l1 rroQA/Ey.

March 5, 1968 n. v. cHENowETH 3,371,717

MULTIPLE y.ZONE WELL PRODUCTION APPARATUS March 5, 1968 D. V. CHENOWETH MULTIPLE ZONE WELL PRODUCTION APPARATUS Filed Sept. 2l, 1965 .o 3an- GO 3b rrOR/VEY.

March 5, 1968 D. v. CHENOWETH 3,371,717

MULTIPLE ZONE WELL PRODUCTION APPARATUS Filed sept. 21, 1965 e sheets-sneer 4 March 5, 1968 D. v. cHENowETH 3,371,717

MULTIPLE ZONE WELL PRODUCTION APPARATUS Filed sept. 21, 1965 6 Sheets-Sheet 5 1520,75.,

March 5, 1968 D. v. CHENOWETH 3,371,717

MULTIPLE ZONE WELL PRODUCTION APPARATUS United States Patent Oil 3,371,717 MULTIPLE ZONE WELL PRODUCTION APPARATUS David V. Chenoweth, Houston, Tex., assignor to Baker Oil Tools, Inc., City of Commerce, Calif., a corporation of California Filed Sept. 21, 1965, Ser. No. 488,943 26 Claims. (Cl. 166--147) ABSTRACT OF THE DISCLOSURE Apparatus for conducting fluid between a plurality of longitudinally spaced production zones in a well bore and the top of the well bore, in which a casing string in the well bore has longitudinally spaced openings or perforations communicating with the zones and a tubing string in the casing string is in sealed relation to one or more packers set in the casing string between the perforations to isolate lthe spaced perforations from one another, a flow regulator being disposed in the tubing string at each zone, this regulator having an orice to reduce the pressure of fluid owing between its associated zone and the tubing string.

The present invention relates to subsurface well bore apparatus, and more particularly to apparatus for conducting well production from a plurality of production zones to the top of the well bore.

There are advantages to producing two or more separate production zones in a well bore through va single tubing string. The capital investment required in multiple completions of a well bore is reduced considerably. The lifting capacity of the well is greatly increased since the comingled production from a plurality of zones ows at a greater velocity through the single tubing string to the top of the well bore. A production zone otherwise non-flowing can be rendered flowing by comingling it with gas from another production zone. Similarly, the flowing life of an initially flowing zone can be extended by its production being comingled with gas from another zone. In the event that production from a single zon'e might be non-commercial by itself, its comingling with production from another zone makes it economical to produce.

It is an object of the present invention to provide improved apparatus for producing a plurality of separate production zones through a single tubing string.

Another object of the invention is to provide apparatus for simultaneously producing a plurality of separate zones through a single tubing string, in which a flow control device for each zone is embodied in the tubing string, and in which the zones are maintained in isolated relation with respect to one another despite removal of one or more of the flow control devices from the tubing string, oiering assurance that production from one zone cannot pass to another zone.

A further object of the invention is to provide apparatus for producing a plurality of separate production zones through a single tubing string, which enables the production rate from each zone to be determined.

Yet another object of the invention is to provide apparatus for producing a plurality of separate production zones through a single tubing string, the production zones being separated from each other in the well bore by packers, the apparatus enabling each packer to be pressure tested or otherwise checked preparatory to simultaneously producing the separate zones.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be 3,371,717 Patented Mar. 5, 1968 ICC embodied. This form is shown in the drawings accompanymg and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a diagrammatic view of apparatus disposed in a well bore for simultaneously producing separate production zones through a single tubing string;

FIGS. 2a and 2b are longitudinal sections through a ow control apparatus at a single zone in the well bore, with its parts in one relative condition, FIG. 2b being a lower continuation of FIG. 2a;

FIGS. 3a and 3b together constitute a longitudinal section similar to FIGS. 2a and 2b illustrating the parts in another relative condition, FIG. 3b being a lower continuation of FIG. 3a;

FIG. 4 is a cross-section taken along the line 4-4 on FIG. 3a;

FIG. 5 is a cross-section taken along the line 5 5 on FIG. 3a;

FIGS. 6a and 6b constitute a combined longitudinal section through apparatus at a single zone, with the ow regulating device being run into position by a running-in tool with respect to a surrounding flow control device incorporated in the tubing string, FIG. 6b being a lower continuation of FIG. 6a;

FIGS. 7a and -7b are views corresponding to FIGS. 6a and 6b illustrating the running-in tool in a condition releasing a part of the latch mechanism of the flow regulator, FIG. 7b being a lower continuation of FIG. 7a;

FIGS. 8a and 8b are longitudinal sections corresponding to FIGS. 6a and 6b illustrating the running-in tool in association with the ow regulator after the latter has been latched in position iu the external Valve mechanism and has shifted the latter to an open condition, FIG. 8b being a lower continuation of FIG. 8a.

As disclosed in FIG. 1, it is desired to conduct production simultaneously from a plurality of separate producing zones A, B, C through a single tubing string D, extending within a well casing E located in a well bore F, to the top of the hole. The well casing has one or a plurality of perforations M, N or P at each producing zone through which production can ow. The production from the zones is maintained separate by well packers R, S, T anchored in packed-oli condition in the well casing between producing zones A, B, C, and also above the uppermost producing zone C. These well packers may be of the permanent or retrievable type in suitable sealed relation to the production string D which extends from the lowermost production zone A through all of the packers to the top of the hole. The packers might be o set individually at their desired locations in the well casing preparatory to lowering the production tubing D in the well bore and placing it in sealed relation thereto, or one or more of the packers may be connected to the production tubing string and lowered therewith into the well bore and appropriately set in the well casing E. The particular packers R, S, T employed do not per se form part of the present invention and may be of any suitable type known in the art.

Production from a lowermost zone A will flow through side ports 10 in a device 11 forming part of the tubing string D and into a ow regulator 12 therewithin, unseating a check valve 13 and then passing through a choke orifice 14 and out of the regulator 12 into the tubing string for upward passage therethrough to the top of the hole. Similarly, separate valve devices 11a, 11b and iiow regulators 12a, 12b are incorporated in the production tubing D between each packer and below the lower packer R, the production from each zone flowing into its associated valve device 11, 11a, 11b and fiow regulator 12, 12a, 12b and thence into the tubing string D. The check valves 13 will prevent fiuid in the tubing string from passing in a reverse direction back into the well casing E and through the casing perforations M, N or P to a producing zone so as to prevent comingling between the zones. The choke orifice 14 will reduce the pressure of the fluid being discharged from the regulator into the production tubing, so that the pressure in the latter is less than the zone pressures, the comingled production from all of the zones owing upwardly through the production tubing string D to the top of the well bore.

In FIGS. 2a to 3b, inclusive, one of the valve devices 11 and regulators 12 is shown and will be described in detail. The other valve devices 11a, 11b and regulators 12a, 12b may be the same. Each device can be placed in either an open or a closed condition. Such well device 11 includes an upper housing sub 15 threadedly secured to a section of the tubing string D thereabove, this housing sub also being threadedly attached to a main housing 16 extending downwardly therefrom to a lower housing sub 17, to which it is threadedly attached, this lower housing sub, in turn, being threadedly attached to a section of the tubing string D therebelow. Spaced inwardly of the housing 16 is a fixed sleeve 18 that provides an annular space 19 with the housing, this sleeve being secured in spaced relation to the housing by a plurality of nipples 20 welded, or otherwise secured, to the housing and to the sleeve, which furnish the side ports establishing communication between the exterior of the housing 16 and the interior of the fixed sleeve 18. A sleeve valve 21 is adapted to be disposed across the nipples or ports 10 to close the latter, or to be shifted downwardly within the fixed sleeve to place its side inlet ports 22 in communication with the housing and sleeve ports 10. This fixed sleeve includes a lower imperforate portion 23 having side seals 24, 25 adapted to be in sealing relation with the fixed sleeve on opposite sides of its ports 10, and also having an upper seal 26 above the valve sleeve ports 22 adapted to seal with the inner surface of the fixed sleeve 18.

The upper position of the valve sleeve 21 within the housing 16, 18 to close the ports 10 is determined by engagement of a stop shoulder 27 on the sleeve with the lower end 28 of the upper sub 15. The valve sleeve 21 has a plurality of circumferentially spaced upwardly extending spring-like latch arms 29 thereon having latch dogs 30 at their upper ends adapted to be received within an enlarged bore or circumferential groove 31 in the sub 15, which will releasably latch the valve sleeve 21 in its upper, port closing position. When the latch dogs 30 are disposed within the enlarged bore 31, inwardly directed coupling fingers 32 on the dogs are disposed outwardly of the passage diameter through the tubing string D and the valve sleeve. When the valve sleeve 21 is shifted downwardly within the housing 16, as described hereinbelow, it can move to an extent in which a valve shoulder 33 engages the upper end 34 of the fixed sleeve, the lower side 35 of the enlarged bore 31 engaging the tapered lower sides 36 0f the dogs 30 and shifting them inwardly to a position in which the fingers 32 project to a slight extent within the tubing passage diameter. With the valve sleeve shoulder 33 engaging the upper end 34 of the fixed sleeve, the valve sleeve ports 22 are in alignment with the housing ports 10 (FIG. 3a), fluid being permitted to flow therethrough.

The valve sleeve 21 is shifted between its port opening and port closing position by the flow regulator 12 adapted to be disposed within the valve sleeve 21 and latched within the housing 16. This fiow regulator includes a mandrel or body 37 composed of a plurality of interconnected sections. It includes an upper tubular mandrel lock section 38 having a peripheral groove 39 into which the dog fingers 32 are shiftable. The lock section carries one or a plurality of downwardly facing lock dogs 40 disposed in longitudinal grooves 41 in the exterior of the mandrel and pivotally mounted on hinge pins 42 secured to the mandrel. Each lock dog is adapted to engage an upwardly facing shoulder 43 on the upper or collet portion of the valve sleeve 21, being urged outwardly into an elongate groove 44 in the latch arms, terminating at its lower end in such lower upwardly facing shoulder `43, by a helical compression spring 45. When the lock dogs 40 are swung outwardly into the latch arm groove 44, their upper retracting nose portions 46 project inwardly of the tubular mandrel 38 into its central passage 47, as disclosed in FIG. 2a.

The lock mandrel section 38 also carries one or a plurality of upwardly holding lock dogs 48 mounted in longitudinal grooves 41 in the mandrel on hinge pins 49 fixed to the mandrel, the upper end of the dog being urged outwardly by a helical compression spring 50. When the valve sleeve 21 has been shifted to its downward port opening position, such as disclosed in FIG. 3a, the spring 50 will shift each upwardly holding lock dog 48 into the enlarged housing bore 31 where they can engage the upper end 51 of the bore and prevent upward movement of the valve sleeve 21 from its port opening position. At this time, the lower retracting nose portions 52 of the upwardly holding dogs project into the tubular mandrel passage 47, as disclosed in FIG. 3a.

The lower end of the lock section 38 of the mandrel 37 is threadedly secured to a port section 53 which includes a `solid head 54 carrying a suitable upper seal 55 adapted to seal against the wall of the valve sleeve 21, this seal being disposed between an upwardly facing shoulder 56 on the port section and the lower end of the lock section 38. Below the solid head 54, the port section has a plurality of ports 57 communicating with the inlet ports 22 through the valve sleeve 21 when the downwardly facing lock dogs 40 engage their companion shoulder 43, fluid owing through the side ports 57 passing to a central passage 58 through the port section and downwardly through a tubular section 59 secured thereto', there being a 4suitable lower seal or seal structure 60a on the tube section sealing against the inner wall of the valve sleeve below its inlet ports 22.

The lower end of the tube section 59 is threadedly secured to 'a regulator valve housing 60, the lower end of which is threadedly attached to its valve body 61 that has a plurality of throttle side ports 62. The lower end of this valve body below its ports is closed by a plug 63 inserted therewithin and having a flange 64 engaging a companion body shoulder, the plug being held therein by a suitable snap ring 65 overlying the plug and disposed in a `circumferential internal groove 66 in the body 61. A suitable seal ring 67 is mounted on the plug to seal against the inner wall 68 of the valve body.

Slidably mounted within the regulator valve housing `60 is a valve sleeve 69, which is adapted to be disposed variously across the body ports 62, to throttle the flow of iiuid therethrough. This valve sleeve has a check valve ball 13 resting upon its upper end adapted to move upwardly into engagement with a downwardly facing check valve seat 71 to prevent upward ow of fluid through the housing 60 and into the tubular mandrel section 59. Upward shifting of the valve sleeve 69 occurs under the influence of a helical compression spring 72 within the housing surrounding the sleeve 69, its upper end bearing against a downwardly facing shoulder 73 at the upper portion of the valve sleeve and its lower end bearing against a ring 74 that has a tapered surface 75 engaging a seal ring 76 and tending to urge the latter frictionally against the periphery of the sleeve. The spring 72 normally tends to shift the regulator valve sleeve 69 upwardly to a position in which its lower end 77 fully opens the body ports 62. A continuation of upward movement of the valve sleeve will effect engagement of the lcheck valve 13 with its companion seat 71.

Fluid flows downwardly through the mandrel tube 59 and around the check Valve ball 13 and in through ports 78 in the upper portion of the sleeve to the central passage 7,9 of the latter, such uid passing downwardly through a choke orifice 14 provided in an orifice plate 80 engaging a downwardly facing sleeve shoulder 81, the plate -being held against such shoulder by a split snap ring 82 engaging the lower end of the plate and disposed within an internal groove 83 in the sleeve 69. The liuid liowing downwardly through the choke orifice 14 creates a pressure differential, tending to shift the orifice plate 80 and the sleeve 69 in a downward direction, causing the lower end 77 of the sleeve to shift across the body ports 62 and change their effective flow area. By appropriately throttling the ow of fluid through the body ports 62, a desired pressure differential of a constant value can be maintained across the orifice plate 80, insuring a constant volumetric rate of flow of uid therethrough.

Assuming that the flow regulator device 12 has been appropriately disposed within the valve sleeve 21 and has shifted the valve sleeve downwardly to the port opening condition illustrated in FIGS. 3a and 3b, fluid from a production zone, such as zone A, will pass through the casing perforations M to the interior of the casing and thence inwardly through the housing ports and the open valve sleeve inlet ports 22, flowing through the side ports S7 of the mandrel to the interior of the latter, and then downwardly around the check valve 13 and into the central passage 79 through the regulator valve sleeve 69, flowing through the orifice 14 and out through the side ports 62 into the tubing string D. -The fluid will then iiow upwardly within the housing 16 and through the annular passage 19 between the fixed sleeve 18 and the housing 16, flowing around the nipples 20 and upwardly through upper ports 86 in the valve sleeve 21 to the interior of the latter above the upper seal 55, the fluid then iowing upwardly around the exterior of the lock section 38 of the mandrel, as well as through its ports 87 to its interior 47, into the tubing string D thereabove. During such flow, the liow regulator valve sleeve 69 can shift, in the event the pressure differential across the orice plate 80 tends to vary, for the purpose of maintaining the pressure differential at a substantially constant value, and thereby assuring that fluid from the particular zone A flows into the tubing string at a controlled rate. If the fluid tends to iiow revers-ely from the tubing string D back into the zone A, such action is prevented -by the upward closing action `of the ball check valve 13 against its companion seat '71.

As stated above, and as disclosed in FIG..1, there is a selectively operated Valve 11, 11a or 11b and a flow regulator 12, 12a or 12b for each zone mounted in the tubing string D, and the production from each zone will pass through the selectively operated valve when it is in open condition and through its ow regulator into the tubing string, the production from all zones comingling and passing upwardly through the tubing string D to the top of the well bore. Initially, however, the valves 11, 11a, 11b are all in the closed condition shown in FIG. 2a, so that fluid canot ow from any of the producing zones into the tubing string. After the packers R, S, T have been set, each valve sleeve 21 can be shifted individually to an open condition (before installation of its flow regulator) for the purpose of applying pressure therethrough into the well casing, so as to test the packer above a particular valve device 11, 11a, 11b and be assured that it is properly anchored in packed-olf condition in the well casing, whereupon the valve sleeve 21 can be reclosed. The vmechanism for shifting the valve sleeve 21 is known -and need not be illustrated nor described herein.

After the packers have been tested, the lower flow regulator valve 12 can then be lowered through the tubing string D on a running-in and setting tool 100, such as disclosed in FIGS. 6a to 8b, inclusive. The lower end of a wire line running-in string 101 is suitably `secured to an adapter 102 attached to a head 103, which is, in turn, attached to the upper end of a running-in tool body 104, which is surrounded by a collet 105. This collet includes an upper portion 106 slidable along the body and urged in a downward direction by a helical compression spring 107, bearing against the head 103 and against a collet shoulder 108. Depending from the upper portion 106 of the collet are a plurality of circumferentially spaced spring-like legs 109 terminating-in feet 110, which are urged downwardly by the spring 107 into a position surrounding. a backing portion 111 of the body 104 and in engagement with the upper shoulder 112 of a sleeve 113 initially secured to the body by one or more shear screws or pins 114. When the feet engage the shoulder 112 vand surround the backing portion 111 of the body, they will project outwardly to a greater effective diameter than the internal diameter of the valve sleeve 21. However, the feet can engage the valve sleeve, or other restriction in the tubing string, which will shift the collet 105 upwardly along the body 104 and locate its feet 110 opposite a smaller diameter portion 115 of the body, wherein they can be sprung inwardly to a smaller effective diameter `capable of passing through the valve sleeve 21, or like restriction in the tubing string D.

The lower end of the body 104 is threadedly secured to a housing 116 depending therefrom which engages the upper end 117 of the mandrel lock section 38 of the flow regulator and operator 12 for the valve sleeve 21. This housing is surrounded by a sleeve 113, the upper end 118 of the housing 116 being initially spaced a short distance below an upper sleeve flange 119 and also being secured to the sleeve 113 by a shear pin 120 extending therethrough and also through -a plunger 121 disposed downwardly within the housing 116 and projecting from its lower end into the lock mandrel 38 of the regulator mechanism. An extension 122 of the plunger initially engages the noses 52, 46 of both the upwardly holding and downwardly holding latches 48, 40 and retracts them inwardly within the confines of the mandrel, as illustrated in FIGS. 6a, 6b, such that the latch dogs cannot catch or engage any member during lowering of the running tool 100 and regulator device 12 in the tubing D and through the selectively operated valves 11, 11a, 11b. The lower end of the sleeve 113 is releasably secured to the lock mandrel 38 by one or more shear screws or pins 123.

In the event the shear screws 114 are released and the outer portion of the shear pin 120 is released, the sleeve 113 can drop downwardly and shift the mandrel lock section 38 downwardly along the plunger 121, 122 to an extent at which the noses 46 of the downwardly holding lock dogs 40 are moved from the retracting plunger 122, whereupon the springs 45 can move the dogs 40 outwardly. In the event the shear pin 120 is further sheared to release the plunger 121 from the housing 116, a helical compression spring 124 surrounding the plunger, with its upper end engaging the upper plunger head 121a and its lower end bearing against the lower housing ange 12S, will expand to further elevate the plunger 121, 122 within the housing 116 and sleeve 113, and also within the tubular mandrel 38, to remove its retracting extension 122 from the noses 52 of the upwardly holding dogs 48, allowing the helical compression springs 50 to shift them outwardly where they can engage their companion locking shoulder 51.

Initially, the running tool 100 has its parts occupying the positions disclosed in FIGS. 6a and 6b, with the plunger extension 122 retaining both the upwardly facing and downwardly facing dogs 48, 40 in their retracted position, and with the tubular mandrel 38 secured to the sleeve 113 of the running-in tool by the one or more shear screws or pins 123. With the latches 40, 48 retracted, the ow regulator device 12 can be lowered in the tubing string D and will pass downwardly therethrough and through all of the selective valve devices 11b, 11a, 11 to a position below the lowermost device 11, the feet 110 of the collet 105 engaging restrictions and shifting the collet upwardly so that the feet can be forced laterally inwardly and pass through such restricted portions, such as the valve sleeve 21 and the lower housing sub 17 of each selective valve device. Upon lowering of the running-in tool and the regulator valve below the lowermost housing sub 17, it can be elevated. Since the collet 105 is then disposed in an enlarged bore of the tubing string D, the spring 107 will shift its feet 110 downwardly, where they engage the upper end 112 of the sleeve 113 and are disposed around the backing portion 111 of the running-in tool body 104. Elevation ofthe apparatus can continue until the feet 110 engage the lower tapered end 17a of the lower housing sub 17, which has a passage diameter the same as the passage diameter through the valve sleeve 21. Further upward movement of the collet 105 cannot occur, so that an upward strain taken on the wire line running-in string 101 and of the running-in tool 100 will effect a shearing of the screws 114 securing the sleeve 113 to the body 104, as well as the outer portion of the shear pin 120 attaching the sleeve 113 to the housing 116, the sleeve 113 moving downwardly until its shoulder 119 engages the upper end 118 of the housing, which will shift the tubular mandrel 38 downwardly along the plunger 121, 122 and release the lower latches 40 from the latter, whereupon their springs 45 can urge them outwardly. The feet 110 of the collet then shift below the backing portion 111 of the body, and such feet engage the tapered end 17a of the lower housing sub to be sprung inwardly for passage upwardly through the lower housing sub 17, as well as through the valve sleeve 21 thereabove, which, of course, is then in its closed position across the housing ports 10. The released downwardly facing latches 40 can shift freely through the restrictions, moving inwardly against the force of their springs 45 (FIGS. 7a, 7b).

When the running-in tool 100 and the dogs 48, 40 have been disposed above the valve sleeve 21, as in the tubing section thereabove, the wire line running-in tool and regulator can be lowered in the tubing string, the downwardly locking dogs 40 shifting outwardly into the groove 44 of the latch `arms 29 and coming to rest against the upwardly facing shoulder 43 of the valve sleeve 21. A downward jarring action can now be imposed upon the apparatus through suitable manipulation of the wire line 101, which will shift the valve sleeve 21 downwardly, the latch dogs 30 being cammed inwardly into the reduced bore 170 of the upper housing sub 15 to place their fingers 32 within the peripheral groove 39 of the mandrel section 38. Downward movement of the valve sleeve 21 occurs until its shoulder 33 engages the upper end 34 of the fixed housing sleeve 18, in which the inlet ports 22 are aligned with the housing ports 10, and with the seal rings 26, disposed on opposite sides of such ports. The downward jarring action imposed on the running-in tool disrupts the shear pin 120 securing the plunger 121 to the housing 116 (the lower end of the plunger engaging the lower dogs 40), allowing the spring 124 to expand and shift the plunger 121 upwardly to remove its extension 122 from engagement with the noses 52 of the upwardly holding latches 48, the springs 50 expanding the latches or lock dogs 48 outwardly. When the valve sleeve 21 has been shifted to its downward port opening position, the upwardly facing latch dogs 48 will be disposed opposite the enlarged bore 31 of the upper housing sub 15, expanding into such bore and being engageable with the downwardly facing shoulder 51 of the upper housing sub to lock the mandrel 37 in place and the valve sleeve 21 in its port open condition, such as disclosed in FIGS. 8a, 8b.

An upward jarring action can now be taken on the running-in string 101 and the running-in tool 100 connected thereto, which will disrupt the shear screws or pins 123 securing the sleeve 113 to the mandrel lock section 38,

allowing the running-in tool to be elevated in the tubing string D and removed from the well bore.

The next ow regulator 12a can then be secured to the running-in string 101 in the same manner as the flow regulator 12 described above and lowered through the next selective valve 11a and the foregoing operation repeated for releasing the downwardly holding latches 40, effecting a downward shifting of the valve sleeve 21 to its port opening condition and the release of the upwardly holding latches 48 and their extension into locked relation within the enlarged bore 31 of the housing sub 15, as disclosed in FIGS. 8a, 8b and also in FIGS. 3a, 3b. The running-in tool 100 is again removed and the next flow regulator 12b connected thereto and lowered in the tubing string and placed in communication with the next selective valve device 11b in upward sequence within the well casing, after which such next valve sleeve 21 is shifted to open position, the regulator valve locked thereto and within the housing, and the running-in string 101 and tool 100 removed from the tubing string.

All of the regulator valves 12, 12a, 12b have now shifted their valve sleeves 21 to open position and are in a locked-in position. Production from each zone A, B, C can flow through its associated Casing perforations M, N, P into the well casing E below the lowermost packer R vand between the packers R, S, T, flowing through the housing ports 10, valve sleeve ports 22, and mandrel ports 57 into the tubular mandrel section 59, flowing downwardly around the check valve 13 and through the valve sleeve 69 and its orifice 14 for discharge through the valve body ports 62 into the tubing string D, thence passing upwardly in the tubing string through the annular space 19 between the fixed sleeve 18 and housing 16 and into the tubing string thereabove. The production from the several zones commingles and passes upwardly through the tubing stringv to the top of the well bore. The differential flow regulator valves retain the desired pressure differential across the orifice plates 80 and insure the passage of production from each zone at the desired rate into the tubing string. The fluid from one zone cannot comingle with fluid from another zone by flowing into such other zone, since it is prevented from doing so by the closing action of each check valve 13, which will engage its companion seat 71 in the event reverse flow tends to occur.

The removal of a flow regulator 12, 12a, 12b can only occur in connection with shifting of its associated valve sleeve 21 back to its upper position closing the housing ports 10. It is to be noted that the fingers 32 of the dogs 30 are held in the mandrel groove 39 by the restricted diameter bore of the housing sub 15. When the flow regulator is to be removed, a suitable retrieving tool (not shown) of a known type is lowered on a wire line in the tubing string. This retrieving tool has a probe (not shown) that will engage the noses 52 of the upwardly holding lock members 48 and will shift them outwardly and the upper lock dog portions of such members inwardly from the enlarged bore 31 of the upper housing sub 15. At the same time, a suitable fishing portion or overshot (not shown) on the retrieving tool moves over the head 117 of the mandrel and becomes locked thereto, in a known manner, which will then permit the mandrel 37 to be elevated. During the initial phase of its elevating movement, it will pull the valve sleeve 21 upwardly with it back to a port closing position until the latch dogs 30 are opposite the enlarged bore 31, which will then spring inherently outwardly under the influence of the spring action of the latch arms 29 into such bore and out of the mandrel groove 39, whereupon the retrieving tool can be elevated on the wire line to elevate the entire flow regulator mechanism therewith through the valve sleeve 21 and through the tubing string D to the top of the hole.

It is to be noted that the regulator valve can only be removed in conjunction with shifting of the valve sleeve F21 to its port closing position. Accordingly, the tubing string is not open to communication with a production Zone through any open ports, preventing iluid from one of the zones from owinginto another Zone. If desired, all of the flow regulator devices 12, 12a, 12b can be removed from the tubing string D and, as a result thereof, all of the valve sleeves 21 will be shifted to their port closing position, thereby insuring that tiiuid from one Iproducing zone cannot ow through the tubing string to another producing zone.

The tubing string 180 below the lowermost selective Valve device 11 can be made of a desired length and with its bottom end 181 closed or bullnosed, as shown in FIG. 1. Because of the spaced arrangement between the fixed sleeve 18 and each surrounding housing 16, in which there is a substantial space 19 therebetween, any sand that might be in the well production will have little tendency to plug or clog the tubing string, since such sand can drop downwardly around the regulating devices and settle into the lowermost section 180 of the tubing string. The sand or other trash will not settle readily in the How passages through the regulator device, including its orice 14.

It is, accordingly, apparent that a multiple zone well production apparatus has -been provided in which a plurality of Zones can be produced through a single string,

with assurance that flow cannot occur between Zones. The

production from each zone assists lproduction from the other zones in flowing through the tubing string to the top of the well bore, the greater velocity of flow through the single tubing string carrying foreign substances, and the like, to the top of the well bore.

I claim:

1. In apparatus for conducting well production from a plurality of production zones to the top of a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production zones from one another; a separate flow regulator in said tubing string at each Zone to conduct fluid from its associated zone into said tubing string; each ow regulator having an inlet to receive fluid from its associated zone and including flow restricting means below said inlet to reduce the pressure of the fluid received from a Zone and to discharge said reduced pressure uid into the tubing string for comingling with reduced pressure fluid in the tubing string from one or more other Zones, the corningled fluid being conducted through the tubing string to the top of the well bore.

2. In apparatus for conducting well production from a plurality of production zones to the top of a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production zones from one another; a separate ow regulator in said tubing string at each zone to conduct fluid from its associated zone into said tubing string; each flow regulator having an inlet to receive fluid from its associated zone and including flow restricting means below said inlet to reduce the pressure of the fluid received from a Zone and to discharge said reduced pressure fluid into the tubing string for comingling with reduced pressure iiuid in the tubing string from one or more other zones, the corningled uid being conducted through the.

tubing string to the top of the well bore; each of said flow regulators including a back pressure Valve to prevent reverse ow of uid therethrough.

3. In apparatus for conducting fluid between a plurality of longitudinally spaced production zones and the top of a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production zones from one another; a separate flow regulator in said tubing string at each zone to conduct fluid between said tubing string and its associated zone; each flow regulator having a port cornmunicating with its associated zone and including iiow restricting means below said port to reduce the pressure of the fluid flowing between its associated zone and the tubing string.

4. In apparatus for conducting fluid between a plurality of longitudinally spaced production zones and the top of a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production zones from one another; a separate flow regulator in said tubing string at each Zone to conduct duid between said tubing string and its associated zone; each flow regulator having a port communicating with its associated zone and including iiow restricting means below said port to reduce the pressure of the Huid flowing between its associated zone and the tubing string; each of said flow regulators including a back pressure valve to prevent reverse iiow of iiuid therethrough.

5. In apparatus for conducting well production from a plurality of production zones to the top of a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production zones from one another; a separate flow regulator in said tubing string at each zone to conduct iiuid from its associated zone into said tubing string; each tlow regulator including a flow restricting oriiice to reduce the pressure of the diuid received from a zone and to discharge said reduced pressure uid into the tubl ing string for comingling with reduced pressure iiuid in the tubing string from one or more other zones, and means for maintaining the iiuid pressure drop across each orifice substantially constant.

6. In apparatus for conducting fluid between a plurality of longitudinally spaced production zones and the top of a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production Zones from one another; a separate flow regulator in said tubing string at each zone to conduct fluid between said tubing string and its associated zone; each flow regulator including a ow restricting orice to reduce the pressure of the iiuid flowing between its associated zone and the tubing string, and means for maintaining the fluid pressure drop across each orice substantially constant.

7. In apparatus for conducting fluid between a plurality of longitudinally spaced production Zones and the top of a well bore: a tubing string `in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production zones from one another; a valve device in said tubing string at each zone, including a housing having a port and valve means shiftable in said housing between port opening and closing positions; iiow regulator means in each housing movable therein to shift said valve means between port opening and closing positions, said flow regulator means including iiow restricting means to reduce the pressure of the iiuid flowing between its associated port and Zone and said tubing string. v

8. In apparatus for conducting fluid between :a plurality of longitudinally spaced production zones and the top of a well bore: a casing string in the Well bore and having longitudinally spaced upper and lower openings communicating with upper and lower production zones, respectively; a tubing string in said casing string; packing means set in said casing string between said upper and lower openings and in sealed relation to said tubing string to isolate said upper and lower openings from one another and the production zones from one another; a valve device in said tubing string at each Zone, including a housing having a port and valve means shiftable in said housing between port opening and closing positions; flow regulator means in each housing releasably connectible to the valve means therein to shift said valve means between port opening and closing positions, said flow regulator means including flow restricting means to reduce the pressure of the uid flowing between its associated port and zone and said tubing string.

9. In apparatus for conducting fluid between a plurality of longitudinally spaced production zones and the top ot' a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production Zones from one another; a valve device in said tubing string at each zone, including a housing having7 a port and valve means shiftable in said housing between port opening and closing positions; flow regulator means in each housing movable therein to shift said valve means between port opening and closing positions, said flow regulator means including a flow restricting orifice to reduce the pressure of the fluid owing between its associated port and zone and said tubing string, and means for maintaining the fluid pressure drop across said orifice substantially constant.

10. In apparatus for conducting fluid between a plurality of longitudinally spaced production zones and the top of a well bore: a casing string in the well bore and having longitudinally spaced upper and lower openings communicating with upper and lower production zones, respectively; a tubing string in said casing string; packing means set in said casing string between said upper and lower openings and in sealed relation to said tubing string to isolate said upper and lower openings from one another and the production zones from one another; a valve device in said tubing string at each zone, including a housing having a port and a sleeve shiftable in said housing between port opening and closing positions; and ow regulator means in each housing releasably connectible to said sleeve therein to shift said sleeve between port opening and closing positions, said ow regulator means being adapted to conduct fluid between its associated port and zone and said tubing string when said sleeve is in port opening position.

11. In apparatus for conducting fluid `between a plurality of longitudinally spaced production zones and the top of a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production zones from one another; a valve device in said tubing string at each Zone, including a housing having a port and a sleeve shiftablc in said housing between port opening and closing positions; and flow regulator means in each housing releasably connectible to said sleeve therein to shift said sleeve between port opening and closing positions, said ow regulator means being adapted to conduct lluid between its associated port and zone and said tubing string when said sleeve is in port opening position; each of said ow regulator means being constructed and arranged for movement through the tubing string Ibetween the top of the Well bore and its associated housing and the sleeve therein; a flow regulator means for a lower zone being movable through a valve device for an upper zone to the valve device for the lower Zone.

12. In apparatus for conducting uid between a plurality of longitudinally spaced production zones and the top of a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production zones from one another; a valve device in said tubing string at each Zone, including a housing having a port and a sleeve shiftable in said housing between port opening and closing positions; and llow regulator means in each housing releasably connectible to said sleeve therein to shift said sleeve between port opening and closing positions, said llow regulator means including a ow restricting orice to reduce the pressure of the fluid owing between its associated port and zone and said tubing string when said sleeve is in port opening position, and means for maintaining the uid pressure drop across said orifice substantially constant.

13. In apparatus for conducting lluid between a plurality of longitudinally spaced production Zones and the top of a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production zones from one another; a valve device in said tubing string at each zone, including a housing having a port and valve means shiftable in said housing between port opening and closing positions; flow regulator means in each housing movable therein to shift said valve means between port opening and closing positions, said flow regulator means including a valve body having a port, a sleeve valve movable across said body port to control the effective area thereof to throttle the flow of fluid through said body port, and orilice means secured to said sleeve valve to reduce the pressure of fluid flowing between its associated housing port and zone and said tubing string and to shift said sleeve valve relative to said valve body port.

14. In apparatus adapted to be disposed in a tubular string in a well bore: a housing having a side port; a sleeve shiftable in said housing between positions opening and closing said port; and flow regulator means in said housing movable therein to shift said sleeve between port opening and closing positions, said ow regulator means including a ow restricting orifice to reduce the pressure of the fluid flowing between said port and tubing string when said sleeve is in port opening position, and means for maintaining the fluid pressure drop across said orice substantially constant.

1S. In apparatus adapted to be disposed in a tubular string in a well bore: a housing having a side port; a sleeve shiftable in said housing between positions opening and closing said port; and flow regulator means in said housing movable therein to shift said sleeve between port opening and closing positions, said flow regulator means including a valve body having a port, a sleeve valve movable across said body port to control the effective area therethrough through which uid can flow, and orifice means secured to said sleeve valve to reduce the pressure of the nid llowing between said housing port and tubing string and to shift said sleeve valve relative to said valve body port.

16. In apparatus adapted to be disposed in a tubular string in a well bore: a housing having a side port; a sleeve shiftable in said housing between positions opening and closing said port; latch means on said sleeve for releasably securing said sleeve to said housing in port closing position; ow regulator means adapted for movement into sealed relation to said sleeve and releasably connectible to said sleeve to shift said sleeve between port opening and closing positions, said flow regulator means including flow restricting means to lreduce the pressure of the fluid flowing between said port and tubular string when said sleeve is in port opening position, said latch means being released from said housing and engaging said housing to be shifted thereby inwardly into coupling engagement with said flow 'regulator means upon shifting of said sleeve to port opening position, said latch means being released from coupling engagement with said flow regulator means upon shifting of said sleeve to port closing position.

17. In apparatus adapted to be disposed in a tubular string in a well bore: a housing having a side port; a sleeve shiftable in said housing between positions opening and closing said port; latch means on said sleeve for releasably securing said sleeve to said housing in port closing position; flow regulator means adapted for movement into sealed relation to said sleeve and releasably connectible to said sleeve to shift said sleeve between port opening and closing positions, said flow regulator means including a valve body having a port, a sleeve valve movable across said body port to control the effective area thereof through which fluid can ow, orifice means secured to said sleeve valve to reduce the pressure of the iluid flowing between said housing port and said tubular string and to shift said sleeve valve relative to said valve body port, said latch means being released from said housing and engaging said housing to be shifted thereby inwardly into coupling engagement with said flow regulator means upon shifting of said sleeve to housing port opening position, said latch means being released from coupling engagement with said ow regulator means upon shifting of said sleeve to housing port closing position.

18. In well apparatus adapted to be disposed in a tubular string in a well bore: a housing; a sleeve fixed to said housing in spaced relation thereto to provide a passage therebetween; said housing and sleeve having port means establishing communication between the exterior of said housing and the interior of said sleeve; a sleeve shiftable in said fixed sleeve between positions opening and closing said port means; and flow regulator means in said shiftable sleeve and movable in said housing to shift said shiftable sleeve between positions opening and closing said port means, said ilow regulator means including flow restricting means to reduce the pressure of the iiuid iiowing between said port means and said passage when said shiftable sleeve is in position opening said port means.

19. In well apparatus adapted to be disposed in a tubular string in a well bore: a housing; a sleeve fixed to said housing in spaced relation thereto to provide a passage therebetween; said housing and sleeve having port means establishing communication between the exterior of said housing and the interior of said sleeve; a sleeve shiftable in said tixed sleeve between positions opening and closing said port means; and flow regulator means in said shiftable sleeve and movable in said housing to shift said shiftable sleeve between positions opening and closing said port means, said flow regulator means including a ow restricting orifice to reduce the pressure of the fluid flowing between said port means and said passage when said shiftable sleeve is in position opening said port means.

20. In apparatus adapted to be disposed in a tubular string in a Well bore: a housing; a sleeve Xed to said housing in spaced relation to provide a passage therebetween; said housing and sleeve having port means establishing communication between the exterior of said housing and the interior of said sleeve; a sleeve shiftable in said fixed sleeve between positions opening and closing said port means; latch means on said shiftable sleeve for releasably securing said shiftable sleeve to said housing in a position closing said port means; iiow regulator means adapted for movement into sealed relation to said shiftable sleeve and releasably connectible to said shiftable sleeve to shift said shiftable sleeve between positions opening and closing said port means, said flow regulator means including flow restricting means to reduce the pressure of the iiuid ilowing between said port means and said passage when said shiftable sleeve is in position opening said port means.

21. In apparatus as deined in claim 18; including stop means on said shiftable sleeve engaging said rxed sleeve to locate said shiftable sleeve in position opening said port means.

22. In apparatus as defined in claim 20; including stop means on said shiftable sleeve engaging said fixed sleeve to locate said shiftable sleeve in position opening said port means.

23. In apparatus for conducting well production from a plurality of production zones to the top of a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production zones from one another; a separate iiow regulator in said tubing string at each zone to conduct uid from its associated zone into said tubing string; each ow regulator having an inlet to receive iiuid from its associated zone and including flow restricting means below said inlet to reduce the pressure of the uid re- Cir ceived from a zone and to discharge said reduced pressure fluid into the tubing string for comingling with reduced pressure fluid in the tubing string from one or more other zones, the comingled fluid being conducted through the tubing string to the top of the well bore; and means providing a fluid passage between at least one of said ilow regulators and tubing string through which iluid moving through its iiow restricting means can move upwardly into said tubing string above said flow regulator.

24. In apparatus for conducting well production from a plurality of production zones to the top of a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production zones from one another; a separate flow regulator in said tubing string at each Zone to conduct fluid from its associated zone into said tubing string; each iiow regulator having an inlet to receive uid from its asociated zone and including ow restricting means below said inlet to reduce the pressure of the fluid received from a Zone and to discharge said reduced pressure tluid into the tubing string for comingling with reduced pressure uid in the tubing string from one or more other zones, the comingled iiuid being conducted through the tubing string to the top of the well bore; and means releasably connecting each regulator to said tubing string to prevent upward movement of said regulator in said tubing string.

25. In apparatus for conducting fluid between a plurality of longitudinally spaced production zones and the top of a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production zones from one another; a separate flow regulator in said tubing string at each zone to conduct fluid between said tubing string and its associated zone; ea-ch iiow regulator having a port communicating with its associated zone and including ow restricting means below said port to reduce the pressure of the fluid iiowing between its associated zone and the tubing string; and means releasably connecting each regulator to said tubing string to prevent upward movement of said regulator in said tubing string.

2-6. In apparatus for conducting fluid between a plurality of longitudinally spaced production Zones and the top of a well bore: a tubing string in the well bore; packing means set in the well bore in sealed relation to said tubing string to isolate the production zones from one another; a separate flow regulator in said tubing string at each Zone to conduct fluid between said tubing string and its associated zone; each flow regulator having a port communicating with its associated zone and including flow restricting means below said port to reduce the pressure on the fluid flowing between its associated zone and the tubing string; and means providing a uid passage between at least one of said ow regulators and tubing string through which fluid can pass between its flow restricting means and said tubing string above said ilow regulator.

References Cited UNITED STATES PATENTS 2,227,539 1/1941 Dorton 166-224 2,537,066 1/l951 Lewis 166-191 2,839,144 6/1958 Ault 166-224 2,976,931 3/i196l Daft-in 166-217 3,045,759 7/ 1962 Garrett et al. 166--224 3,194,312 7/1965 Thomas 1'66-45 3,282,341 11/1966 Hodges 166-45 JAMES A. LEPPINK, Primary Examiner. 

